Shares of Abivax tumbled as a lot 32% after it reported contemporary information on its lead asset, a drug for ulcerative colitis, wiping out billions in market cap and elevating questions over how a possible takeover of the French biotech may unfold.
The medication met its endpoints of demonstrating clinically significant efficacy and a placebo-adjusted remission charge of about 40% for each doses examined, but in addition confirmed that there have been most cancers circumstances amongst sufferers taking the upper dose.
“[The] most cancers sign complicates issues,” a Jefferies analyst mentioned. “Even when unrelated noise, we predict the overhang will likely be actual, particularly contemplating absence of different value-inflecting information occasions over the subsequent [year].”
Within the examine cohort, there was one reported case every of prostate most cancers, breast most cancers, and colonic dysplasia, which Abivax mentioned had been thought-about unrelated to therapy by investigators, with no organ-specific clustering noticed.
There have been additionally 4 circumstances of pores and skin most cancers on the upper 50 mg dose, of which two had been deemed not or unlikely associated to the drug, and the opposite two had a medical historical past of pores and skin most cancers, Abivax mentioned.
The Jefferies analysts mentioned that “an affordable rationalization” for the most cancers circumstances was believable however “does not appear to be an simply dismissed overhang,” and downgraded the inventory to Maintain from Purchase.
The Paris-listed inventory gained practically 1,700% in 2025, however shares had fallen 7% coming into Tuesday buying and selling.
It was final buying and selling down 31% to a completely diluted market cap of about 7 billion euros.
Abivax shares year-to-date.
The trial outcomes, printed late Monday, had been from a upkeep examine during which Abivax assessed the impact of the drug, obefazimod, over 44 weeks. It comes after the outcomes of a late-stage trial in mid-2025 beat even essentially the most optimistic expectations.
Analysts have described the experimental drug as a possible best-in-class therapy for ulcerative colitis (UC). Abivax can be testing the drugs for Crohn’s illness, opening it as much as a multi-billion-dollar marketplace for Irritable Bowel Syndrome (IBS).
“The novel mechanism, sustained medical remission, and favorable long-term security profile spotlight its potential to deal with a major unmet want in UC,” mentioned Abivax’s David Rubin, additionally director of the inflammatory bowel illness heart on the College of Chicago Drugs.
“Whereas the malignancy sign can’t be ignored, we view it as a possible labelling overhang fairly than proof of a transparent causal security threat,” mentioned Stifel analyst Damien Choplain, noting that the efficacy information had been robust.
AbbVie’s Rinqvoc, one other medicine for ulcerative colitis and different inflammatory circumstances, carries a U.S. Meals and Drug Administration warning of malignancy however nonetheless generated $8.3 billion in gross sales in 2025, he added.
Takeover goal
Abivax has been positioned as a prime takeover goal, with unconfirmed rumors that huge pharma has its eyes on the clinical-stage biotech led by CEO Marc de Garidel.
De Garidel informed CNBC in March that he was assured the upkeep examine would learn out positively, and signaled that the corporate was in no rush to safe a deal or a partnership, as phrases could be higher after it.
It has been broadly anticipated that Abivax could be acquired earlier than launching obefazimod, and de Garidel informed CNBC that it was planning to boost cash after the June information readout. The corporate on Monday reiterated the expectation to submit obefazimod for FDA approval within the fourth quarter and a possible launch in 2027.
Based on Choplain, the most probably situation now could be that Abivax will await the complete information set, which is anticipated to be disclosed in October, to realize extra granularity and make sure that the malignancies aren’t associated to the therapy.
It additionally appears cheap to imagine that potential consumers will await the complete information set earlier than making a transfer, he informed CNBC through electronic mail on Tuesday.
